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Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration

Kleinfehn, Alex Patrick
http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562

Abstract Details

2019, Doctor of Philosophy, University of Akron, Polymer Science.
Scale-up of end-functionalized poly(propylene fumarate) for academic and industrial research. Scale-up of poly(propylene maleate) (PPM) and poly(propylene fumarate) (PPF) was investigated to examine the control of polymer molecular mass properties, adverse side reactions, and end-group fidelity. Two batches of PPM were synthesized at reaction sizes greater than 100 grams using a round-bottom flask with yields exceeding 90% and narrow molecular mass distributions (DM) below 1.3. Polymerization and isomerization conditions were developed for increasing the reaction size to 5000 grams using a 20-liter process reactor, and yields remained above 80% and DM below 1.4. 1H NMR spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) confirmed end-group fidelity and preservation of the propargyl alcohol initiator under scale-up conditions. This project demonstrates the feasibility of the scale-up and commercialization of PPF and provided material to collaborators for research. Surface availability and dispersal of Bioglass 45S5 in 3D printed poly(propylene fumarate) for bone tissue regeneration. Poly(propylene fumarate) (PPF) shows potential as a material in implantable devices for bone defect repair as it can be 3D printed into degradable scaffolds. The mild hydrophobicity, lack of cell attachment moieties, and osteogenic signals of untreated PPF scaffolds hinders their well-studied osteoinductive properties to aid in bone tissue regeneration. To address this issue, these scaffolds may be coated with both serum albumens and functionalized with tethered whole growth factors or bioactive short peptides ligands. We have previously presented a method of tethering ligands that requires a bioactive ceramic (45S5 Bioglass) be incorporated into PPF resins. However, for this surface functionalization strategy to have success, sufficient Bioglass must present at the surface of 3D printed PPF scaffolds. Our Bioglass-based surface functionalization strategy uses a ligand tethering strategy consisting of catechol-dendron moieties that link micrometer scale Bioglass crystals to the desired ligand proteins to spur bone precursor cell attachment, proliferation, and differentiation leading to bone tissue formation. Analysis shows that Bioglass is available at the surface and catechol functionalization can be modulated based on the concentration of Bioglass in the PPF resin formulations. This shows the surface properties of PPF could be enhanced using Bioglass and can be effective for improving the osteogenic properties of 3D printed PPF scaffolds for clinical applications. Surface modification and quantification of ketone-functionalized poly(propylene fumarate) surfaces. Poly(propylene fumarate) (PPF) was synthesized using 4-hydroxy-2-butanone initiator to introduce ketone functionality for post-polymerization modification through oxime ligation. The 4-hydroxy-2-butanone PPF was characterized using 1H NMR and 13C NMR to confirm preservation of the ketone functional group, and the PPF resin was 3D printed into porous scaffolds for future cell studies. Surface functionalization of 4-hydroxy-2-butanone PPF was quantified using fluorescence microscopy and a fluorescent dye analyte and showed a surface concentration of 3.78 ± 0.15 nmol/cm2, over 50% greater than physical controls. A cell study is planned to modify the surface of scaffolds with short-chain peptide mimics to look at osteogenic differentiation of human mesenchymal stem cells.
Matthew Becker (Advisor)
Junpeng Wang (Committee Chair)
Chrys Wesdemiotis (Committee Member)
Eric Amis (Committee Member)
Rebecca Willits (Committee Member)
136 p.
Biomedical Engineering; Biomedical Research; Chemistry; Materials Science; Plastics; Polymer Chemistry; Polymers
Poly propylene fumarate; PPF; Bioglass; catechol; bone; tissue engineering; 3D printing; additive manufacturing; surface functionalization; scale-up; process reactor; ring-opening polymerization; end-group fidelity; polymerization;

Recommended Citations

Citations

  • Kleinfehn, A. P. (2019). Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562

    APA Style (7th edition)

  • Kleinfehn, Alex. Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration. 2019. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562.

    MLA Style (8th edition)

  • Kleinfehn, Alex. "Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration." Doctoral dissertation, University of Akron, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562

    Chicago Manual of Style (17th edition)

akron1562679460809562
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© 2019, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.